Neural Communication Psychology 2606

Introduction It was pretty clear early on that electricity played a role of some sort in neural communication It was pretty clear early on that electricity played a role of some sort in neural communication Galvani, frogs’ legs and lightning Galvani, frogs’ legs and lightning Fritsch and Hitzig stimulated cortex of various animals, got twitches Fritsch and Hitzig stimulated cortex of various animals, got twitches Bartholow and Mary Rafferty Bartholow and Mary Rafferty Dr. Penfield, I smell burnt toast Dr. Penfield, I smell burnt toast

EEGs are AOK Caton Caton Helmholtz Helmholtz Hodgkin, Huxley and giant axons Hodgkin, Huxley and giant axons Used mircorelectrodes and oscilloscopes to measure the resting potential of a neuron Used mircorelectrodes and oscilloscopes to measure the resting potential of a neuron -70 mV -70 mV

Electrical activity of the neuron Resting potential Resting potential About -70 mV About -70 mV Selectively allowing certain ions in Selectively allowing certain ions in With stimulation Na+ is allowed in With stimulation Na+ is allowed in Action potential Action potential Changes in one area lead to changes in another Changes in one area lead to changes in another Chemical to electrical, very cool Chemical to electrical, very cool

The Sodium Potassium Pump Active transport takes energy Active transport takes energy Easier encoding? Easier encoding? Faster reaction? Faster reaction? An Action potential happens when stimulation causes the pump to sort of stop, Na gets in, K goes out An Action potential happens when stimulation causes the pump to sort of stop, Na gets in, K goes out Sort of reversed later Sort of reversed later

integration Excitatory postsynaptic potentials Excitatory postsynaptic potentials Inhibitory postsynaptic potentials Inhibitory postsynaptic potentials Temporal summation Temporal summation Spatial summation Spatial summation

The axon Hillock Where the axon starts Where the axon starts many voltage sensitive channels many voltage sensitive channels Need oh say -50 mV for depolarization Need oh say -50 mV for depolarization Not all graded potentials are equal Not all graded potentials are equal

Sensation and movement Receptors for Receptors for Light Light Sound Sound Smell Smell Taste Taste Touch Touch Pain Pain Cold Cold heat heat

movement Neuron synapses onto end plate Neuron synapses onto end plate Big channels Big channels Acetylcholine Acetylcholine Ach antagonists can cause paralysis Ach antagonists can cause paralysis Curare Curare Sarin Sarin

EEG Oldest form of brain imaging Oldest form of brain imaging

CAT Scan Computerized axial tomography Computerized axial tomography

PET scan Positron emission tomography Positron emission tomography

MRI Magnetic Resonance Imaging Magnetic Resonance Imaging

ERPs and single cells Event related potentials Event related potentials Used to see what is lit up, pretty cheap Used to see what is lit up, pretty cheap Single cell recording uses micro electrodes Single cell recording uses micro electrodes